/**
 * @import {Color} from "../math/color.ts";
 * @import {Vector2d} from "../math/vector2d.ts";
 */
/**
 * A Trail renderable that draws a fading, tapering ribbon behind a moving object.
 * Points are sampled from a target or added manually, and rendered as connected
 * quads with interpolated width and color.
 * @category Game Objects
 * @example
 * // simple single-color trail following a sprite
 * const trail = new Trail({ target: player, color: "#44aaff", width: 20 });
 * app.world.addChild(trail);
 * @example
 * // gradient trail following a sprite (fire effect)
 * const trail = new Trail({
 *     target: player,
 *     width: 30,
 *     gradient: ["#ffff00", "#ff4400", "#ff000000"],
 * });
 * app.world.addChild(trail);
 * @example
 * // rainbow trail with custom width curve
 * const trail = new Trail({
 *     target: player,
 *     width: 40,
 *     widthCurve: [1, 1, 0.8, 0.4, 0],
 *     gradient: ["#ff0000", "#ff8800", "#ffff00", "#00ff00", "#0088ff", "#8800ff00"],
 * });
 * app.world.addChild(trail);
 * @example
 * // manual mode (e.g. sword slash)
 * const slash = new Trail({ width: 24, lifetime: 200, color: "#ffffff" });
 * app.world.addChild(slash);
 * // call each frame during the attack animation
 * slash.addPoint(swordTip.x, swordTip.y);
 * @see {@link Renderable}
 */
export default class Trail extends Renderable {
    /**
     * @param {object} [options] - trail options
     * @param {Renderable|Vector2d} [options.target] - auto-follow target
     * @param {number} [options.length=20] - max number of points
     * @param {number} [options.lifetime=500] - point lifetime in ms
     * @param {number} [options.minDistance=4] - min distance between samples in px
     * @param {number} [options.width=10] - max trail width in px
     * @param {number[]} [options.widthCurve=[1, 0]] - width multiplier curve (0=head, 1=tail)
     * @param {Color|string} [options.color="#ffffff"] - single trail color. Ignored if `gradient` is set.
     * @param {(Color|string|{pos: number, color: Color|string})[]} [options.gradient] - color gradient. Overrides `color`.
     * @param {number} [options.opacity=1.0] - trail opacity (0.0–1.0)
     * @param {string} [options.blendMode="normal"] - blend mode
     */
    constructor(options?: {
        target?: Vector2d | Renderable | undefined;
        length?: number | undefined;
        lifetime?: number | undefined;
        minDistance?: number | undefined;
        width?: number | undefined;
        widthCurve?: number[] | undefined;
        color?: string | Color | undefined;
        gradient?: (string | Color | {
            pos: number;
            color: Color | string;
        })[] | undefined;
        opacity?: number | undefined;
        blendMode?: string | undefined;
    });
    /** @type {Renderable|Vector2d|null} */
    target: Renderable | Vector2d | null;
    /** @type {number} */
    maxPoints: number;
    /** @type {number} */
    lifetime: number;
    /** @type {number} */
    minDistance: number;
    /** @type {number[]} */
    widthCurve: number[];
    /** @ignore */
    _gradient: Gradient;
    /** @ignore */
    _points: any[];
    /** @ignore */
    _segmentColor: Color;
    /** @ignore */
    _n0: {
        x: number;
        y: number;
    };
    /** @ignore */
    _n1: {
        x: number;
        y: number;
    };
    /**
     * add a point to the trail
     * @param {number} x - x position
     * @param {number} y - y position
     */
    addPoint(x: number, y: number): void;
    /** @ignore */
    update(dt: any): boolean;
    /** @ignore */
    draw(renderer: any): void;
    /** clear all trail points */
    clear(): void;
    /**
     * Build a Gradient from trail constructor options.
     * @param {object} options - trail constructor options
     * @returns {Gradient}
     * @ignore
     */
    _buildGradient(options: object): Gradient;
    /** @ignore */
    destroy(): void;
}
import Renderable from "./renderable.js";
import type { Vector2d } from "../math/vector2d.ts";
import { Gradient } from "../video/gradient.js";
import type { Color } from "../math/color.ts";
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